A prospective randomized clinical trial conducted at twelve centers across the country will examine the effectiveness of supportive/expressive group therapy for 480 women with newly diagnosed stage I, II, and III breast cancer. Three major hypotheses will be addressed: 1) Patients who receive supportive/expressive group therapy will have lower mood disturbance, better quality of life, and better compliance with prescribed medical treatment than patients who do not receive this intervention. 2) Individuals with higher initial mood disturbance, more advanced disease, more treatment side effects, and poorer social support will benefit most from the intervention. 3) This intervention is transferable to the community setting. Therapists at ten community sites and two university settings will be able to adequately learn the therapeutic skills and apply them in a manner that results in improvement in treated patients. Our laboratory has extensive experience in developing and applying group psychotherapy methods to women with metastatic and primary breast cancer. In previous research, we have shown significant reductions in mood disturbance, denial and pain, as well as an unanticipated prolongation of mean survival time among women with metastatic breast cancer who were treated with supportive/expressive group therapy. We have developed treatment manuals and rating instruments for assessing the effectiveness of this structured supportive/expressive group therapy in reducing psychosocial distress. The intervention reduces depression and improves coping by helping patients to deal with their fears of disease progression and death, manage strong emotions, better utilize time through reordering life priorities, enhance relationships with family and friends, improve interactions with health-care personnel, and learn self-management strategies such as relaxation for pain and anxiety control. The next logical step is to apply this treatment earlier in the course of disease by: i) testing the effectiveness of supportive/expressive group therapy in reducing psychosocial distress in newly diagnosed breast cancer patients; ii) exploring mechanisms of effectiveness, and to identify subgroups most likely to benefit; and iii) evaluating implementation of this treatment in a variety of academic and community clinical centers across the United States. This study would provide an empirical basis for widespread programmatic implementation of supportive/expressive group therapy in the treatment of women with breast cancer, resulting in more compassionate, efficient, and effective treatment of cancer patients.